Hi all,
I am doing a trial Ni NVT Reaxff simulation using lammps. The evdwl term in *.pot file goes to zero after the 1st step. This gives energy discrepancies between stand alone reaxff code and lammps implementation. I am using 28March-2012 version. Can you please tell me if this is a known error?
My input file:
units real
atom_style charge
boundary p p p
read_data Ni_900k_bulk.data
thermo_style custom etotal pe ke vol press temp pxx pyy pzz pxy pxz pyz lx ly lz xy xz yz
thermo_modify line multi flush yes
thermo 100
neighbor 2 bin
neigh_modify every 10 delay 0 check no
pair_style reax/c lmp_control_900k_bulk checkqeq no
pair_coeff * * ffield.reax 6
dump 1 all custom 1000 Ni_900k_bulk_nvt.dump id type xu yu zu
timestep 1.0
velocity all create 900.0 4928459 rot yes dist gaussian
fix 1 all nvt temp 900.0 900.0 100.0
run 30000
write_restart Ni_900k_bulk_equil_nvt.rst
The first lines of out file:
---------------- Step 0 ----- CPU = 0.0000 (sec) ----------------
TotEng = -202005.5731 PotEng = -207497.1194 KinEng = 5491.5464
Volume = 23200.0904 Press = -45566.3910 Temp = 900.0000
Pxx = -45353.6837 Pyy = -45474.7288 Pzz = -45870.7606
Pxy = 102.8131 Pxz = -237.9743 Pyz = 321.6566
Lx = 28.5209 Ly = 28.5209 Lz = 28.5209
Xy = 0.0000 Xz = 0.0000 Yz = 0.0000
---------------- Step 100 ----- CPU = 87.5354 (sec) ----------------
TotEng = -276456.3085 PotEng = -279660.9110 KinEng = 3204.6025
Volume = 23200.0904 Press = -27807.2680 Temp = 525.1967
Pxx = -27671.1583 Pyy = -27955.9491 Pzz = -27794.6966
Pxy = 650.9254 Pxz = 136.7142 Pyz = 62.0146
Lx = 28.5209 Ly = 28.5209 Lz = 28.5209
Xy = 0.0000 Xz = 0.0000 Yz = 0.0000
Corresponding lines from the *.pot file generated by lammps
step ebond eatom elp eang ecoa ehb etor econj evdw ecoul epol
0 -611258.41 331621.80 0.00 0.00 0.00 0.00 0.00 0.00 72139.50 0.00 0.00
100 -610570.72 330909.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
regards,
Karthik Guda
Penn State University